In blood transfusion, bone marrow transplantation, or other cell cultures ex vivo, one of the principal problems encountered is that of the preservation of cells. It is critical to be able to preserve cells, under good conditions of viability, for time periods compatible with clinical production and storage, and to make it possible to analyze cell preparations. The most commonly used method of long-term preservation of cells is to freeze and thaw the material. However, during the freezing of cells, loss of viability may occur. This problem can be even more complex when the cells have been modified or altered prior to preservation, and when the cells are obtained by proteolytic digestion of a tissue or tumor specimen. Furthermore, preservation of cells on ice (about 0.degree. C.), refrigerated (about 4.degree. C.), or at room temperature, prior to use, is also difficult.